My ipod nano will not sync all of the songs from my library. it will only sync the newest songs i purchased.

How Do I Download Songs Onto My iPod Nano?
IPod Nanos are portable multimedia players that allow you to playback songs and other content (e.g. video) no matter where you go. They come in a variety of memory sizes such as 4GB or 16GB (gigabytes) and work with iTunes to upload songs. ITunes is the iPod default management program which allows you to upload songs to its library, create playlists and sync music on your iPod quickly and easily. This simple process will have you jamming to your favorite songs in no time.


Downloading to an iPod Nano1Connect your iPod Nano to the computer using the USB cable. Launch iTunes if does not automatically launch. When you launch iTunes, it will display your iPod Nano on the left panel.
2Add music to your iTunes library. Click the "File" button on the top menu and click "Add to Library." Locate the song you want to upload to your player and click "Open" to load it to your program.
3Click the "+" button on the lower left panel to create a playlist. Type a name for the playlist and drag the uploaded file to it. To upload additional songs, repeat Step 2 and drag the uploaded additional songs to the created playlist.
4Drag the songs in the playlist up or down to select the order in which the songs will play.
5Sync your iPod Nano. Click the iPod icon on the left panel after importing songs and adding them to the created playlist. Click the "Music" tab and click "Sync music." Click "Select playlists, artists and genres" and select the playlist you created that contains the songs you want to upload. Click "Apply" to automatically sync and download the songs to your iPod Nano.
6Click the "Eject" button and disconnect your iPod from the computer.

Tips & Warnings
Click "Music Store" if you want to purchase a music file. Search for the song on the iTunes store and download it to the iTunes library.

I think you are trying to sync with a different library than your own original library that you synced your ipod before. OR the original songs that are in your ipod are no longer in your library. There is a option that you could sync songs manually.
1. Connect your iPod 2. Start iTunes 3. Click on your iPod 4. Check option that says Manually sync songs
Now you can sync your music without deleting the old songs. I hope

Once itunes has finished syncing go to your ipod under devies and then click on the music tab and then click on sync music and choose the options you require from entire music library to playlists (my prefered option as you can prior to syncing set up an ipod playlist and add what music you want) or Artist, Genres or Albums. Once you have selected the options you require click on Apply at the bottom right corner. Hope this helps.

The following information has come directly from the apple support web site.

Adding Content Automatically or Manually
There are two ways to add content to iPod nano: ? Automatic syncing: When you connect iPod nano to your computer, iPod nano is automatically updated to match the items in your iTunes library. You can sync all your songs, playlists, videos, and podcasts, or, if your entire iTunes library doesn’t fit on iPod nano, you can sync only selected items. You can sync iPod nano automatically with only one computer at a time. ? Manually managing iPod nano: When you connect iPod nano, you can drag items individually to iPod nano and delete them individually from iPod nano. You can add songs from more than one computer without erasing songs from iPod nano. When you manage music yourself, you must always eject iPod nano from iTunes before you disconnect it.

The following URL will bring you to the iPod Nano manual. For more information on setting up you iPod see chapter 2: Setting up iPod Nano

http://manuals.info.apple.com/en_US/iPod_nano_5th_gen_UserGuide.pdf

I hope that information above has helped is some way.
If possible please rate this solution.

You have to delete songs using itunes.

if you delete from itunes library it will delete it from ipod
if you only want certain things on you ipod then sync to a playlist you create or sync only checked songs .

Apple iPod Nano devices are using itunes.
Every purchase or Apple iPod unit are given a disc which to install iTunes in your Computer.
If you don't have one you can download at this site.
www.yboyandrei.com/itunes

Good luck!

take off automatic sync and just sync the music you want to using manual sync. Automatic sync has parameters. such as it will only sync the newest or most recently added or your playlists that you select. manual sync you just drag from your library and just drop it into your ipod on the left side of itunes. you can try to do this with automatic sync but next time you plug it in it might dissappear.

Your library needs to be rebuilt to version 8.0 before ITunes will work. Once the database is rebuilt, your songs will reappear in Itunes for use.

Give Itunes the library that your files are in using the folder options. Itunes will rebuild the library off of those settings.

Backup your purchased songs asap.

Start with these five simple solutions: Reset, retry, restart, reinstall, or restore
http://www.apple.com/support/ipod/five_rs/

Your iPod syncs the songs in your iTunes library every time you plug it into your computer, adding/removing songs is only a matter of adding/deleting them from your library and re-syncing your iPod.